The Changing Utilization of Neoadjuvant Chemotherapy among Different Racial Groups and Its Effect on Mastectomy Rates.

1040 Background: Neoadjuvant chemotherapy (NAC) has been utilized to downstage disease and to allow breast conservation. There is limited data on the patterns of utilization of NAC among different racial groups. The purpose of this study is to explore NAC use over time among different racial groups and to examine its impact on final surgical procedure. Methods: Women with invasive breast cancer diagnosed between 2004 and 2013 were identified in the National Cancer Database. NAC use over time was determined for the following ethnic groups: non-Hispanic white, non-Hispanic black, Hispanic, and non-Hispanic Asian/Pacific islander. Similarly the use of breast conservation versus mastectomy was also evaluated over time for each racial group. The chi-square test for trend was used to assess the relationship between use of NAC/breast conservation and time, stratified by racial group. Results: Of 1,016,748 patients diagnosed with invasive breast cancer 84,773 received NAC. The rate of NAC utilization increased between 2006 to 2013, from 6.9% to 12% (p < 0.0001) overall. The greatest increase was seen in the non-Hispanic black population, 12% in 2006 to 17.5% in 2013. The majority of patients receiving NAC were stage 2 or 3 across all racial groups and remained consistent over time. Reported rate of pathologic complete response (pCR) increased from 3.5% in 2006 to 25% in 2013 (p < 0.0001); this was observed across all racial groups. From 2006 to 2013, the rate of mastectomy did not change, with approximately 65% of patients each year receiving mastectomy (p = 0.12). When examined by racial group, the proportions of patients receiving mastectomy also did not change over the study period. Conclusions: The use of NAC has doubled between 2006 and 2013, with the greatest increase in utilization seen in the non-Hispanic black population. There has been a concomitant increase in the rates of pCR observed across all racial groups. Despite the increased pCR, there was no change in the number of women having mastectomy over the study period when examined overall or based on racial group.